I nominate my boss. My job requires being on call evenings and weekends to cover emergencies as well as working Saturday mornings (the Saturday schedule is completely her decision to have as the business owner). Being the only two people at our level we split these more or less 50/50 and my contract specifies I will work "1-2 Saturdays per month." This month due to one of her kids' commitments she scheduled me to work 4 out of 5 Saturdays and 2/3 of the on call. I whined to a friend, but gritted my teeth and went along with it. I have been on call two weeks straight with VERY demanding clients and I'm completely exhausted.
Apparently my boss asked the manager who does the day-to-day running of the business (VERY small business) whether she thought I would be willing to cover that fifth Saturday this month so she could do some extra activities for her kid's activity. That would mean being on call all but 10 days this month plus give up every single Saturday. Thankfully our manager told him I have plans, but she's still completely clueless. The same boss also asked if I would be willing to do 24/7 100% on call when our other employee quit since she had to take over her shifts until she bothered to hire someone else. My manager also shot that down. To put on call in perspective last weekend I worked Saturday 9-1, then an emergency in the evening, then hardly had a chance to eat on Sunday from 7 am until 1 am due to emergencies.
My manager isn't perfect, however. I requested some time off over an upcoming holiday. I asked for a total of vacation days left which he calculated including the weekends as vacation days since I "might have been scheduled that weekend." I had to point out every time I was away I worked double on call and lost my normal day off every other week so he actually owed me more than he thought (not to mention killing myself this month with no expected equivalent time off). He huffed, but wrote me in for the time off like it was a huge favor to schedule around.